Iieinrich horn



(MOdeL) H HORN COMBINED RULE AND PROTRAGTOR.

,944. Patented Nov. 26, 1.889.

WITNESSES {Mm Qw UNITED STATES HEINRICH HORN, OF NEWV YORK, N. Y.

PATENT OFFICE: I

, ASSIGNOR OF ONE-HALF TO CHARLES GERl-IARDT, OF SAME PLACE.

COM BIN ED RU LE AN D PROTRACTOR.

SPECIFICATION forming part of Letters Patent No. 415,944, dated November 26, 1889.

Application filed November 3, 1888. Serial No. 289,875. (ModeL) to The invention consists in the construction and combination of parts and details, as will be fully described and set forth hereinafter, and finally pointed out in the claims.

In the accompanying drawings, Figure 1 is a side view of inyimproved combination rule and protractor folded. Fig. 2 is a side View of parts of the same, showing the two legs at an inclination. Fig. 3 is a side view of the same extended. Fig. 4 is a top view of the same extended. Fig. 5 is a detail view of one leg, showing parts broken out and others in section. Fig. 6 is a detail side View of the hinge-piece. Fig. 7 is an end view of the same.

Similar letters of reference indicate corre- 2 5 sponding parts.

The rule is composed of the two legs A and B,which are pivoted to each other in the manner that will now be described. The leg A has its end a shaped on an arc line the center of which is at a. The leg A is provided at its end part with a recess (3 in each side, the inner edges of said recess being formed on a segmental or are line b, the center of which is in the point Z) and in a notch D in the bottom edge of said leg A. The leg A is provided in its end with a recess E, extending from the top to the bottom edge, and in said recess a hingepiece F is placed, the bottom edge of which is a straight line and the top edge of which is 0 composed of two arcs d and f, having their centers at d and f, respectively. The piece F is provided on each side with a meniscusshaped flange G, the outer edge of which is flush with the arc edge f of said piece F, and the inner end of which is formed by an are (P, the center of which is at cl. In the curved edge of said piece F notches h 72 are provided at the top and notches 7L3 and h at the ends. The piece F is placed into the recess E in the 0 end of the leg A, and is pivoted therein by a pin J, passed through apertures a of the leg A and the aperture (1 of the piece F, so as to adapt the piece F to swing in the recessed end of the leg A, with the pin J as center. The outer leg B has its end rounded on the are line g, having its center at g, and is provided with a recess K, extending from top to bottom and of sufficient width to receive the recessed end part of the leg A and the hinge-piece F.

A pivot L is passed through apertures in the leg B and through the aperture f of the piece F. A spring M is secured on the upper edge of the leg 13, and is provided on its free end with a spur N, that can enter the notch 7B". A like spring R is secured on the top edge of the leg A, and is provided on its free end with a' spur S, whichcan enter the notch 7a of the hinge-piece F.

When the implement is folded, as shown in Fig. l, the inner or under edges of the legs A B are in contact and the straight bottom edge of the piece F is at right angles to the longitudinal axis of said legsAand B, and is locked to the leg B by the spring M, the spur N of which is in the notch h The spur S is in the notch h. The legs can be swung from each other until they are at right angles, the spur S snapping out of the notch h and the pin J being the center on which they turn, and the piece F remaining locked to the leg B and the pin L passing into the notch D. In case the leg B is swung outward still farther the spur S snaps into the notch h and the spur N snaps out of the notch 7L2, the spur S preventing the piece F from turning after said piece F has been brought into such position that its bottom edge is parallel with the bottom edge of the rule A. As soon as the spring M is disengaged from the piece F the leg B does not swing on the pin J as center, but on the pin L as the center, and while thus swinging the rounded edge of the leg B rests against and slides along the edge I) of the shoulder O of the leg A.

Protractor-subdivisions are provided on the 5 outer surfaces of the leg B and on the bottom of the recess 0, thus permitting the adjusting of the leg B at any desired angle to the leg A. The meniscus-shaped flange G serves forguiding the piece F on the rounded edges a of the ICC leg A. To fold the rule, the sameis first swung into position with the leg B at right angles to the leg A, the pinL being the center on which the leg B turns, and then the spur N of the spring M snaps into a notch h of the piece F, and as the leg B is swung against the inner edge of the leg A it turns with the piece F 011 the pin J as center.

It will be observed that the inner edges of the legs always form a clear corner whenever the legs are at any angle to each other, thus adapting the instrument for measuring all angles, as the inner edges of the legs can be applied directly upon the faces of the articles or object the angle of which is to be measured.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A combination rule and protractor consisting of two legs united by a hinge-piece, the bottom edge of which is a straight line and the top edge of which is formed of two eccentric arcs of circles the centers of which are a short distance from each other, said hingepiece being pivoted by apin to one leg and by another pin to the other leg, substantially as set forth.

2. The combination, with two legs having recessed ends, of ahinge-pieceinserted in said legs and engaging said hinge-piece, substantially as set forth.

3. The combination,with the leg A, having the rounded end edge a, the recesses C, and the notches D in the bottom edge, of the leg B, having the rounded edge and the recess K, the hinge-piece F, having the meniscusshaped flanges G, and the springs M and R, secured on the legsA and B and engaging the hinge-piece F, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of subscribing two Witnesses.

HEINRICH HORN. Witnesses:

CARL KARP, JOHN A. STRALEY. 

